Streamlight ProTac HL USB Charging

I recently bought a ProTac HL USB, which I like very much. It's well built and seems very robust, with a blend of throw and flood that meets my needs perfectly.

It takes about 8 hours to fully charge because the maximum charging rate appears to be around 360mA. I noticed, however, that it also took about 8 hours to charge if only partly discharged, or if I plugged it back in immediately after completing a charge (I base this upon the time it takes for the charging light to turn from red to green). I called Streamlight customer support and they said that there were some problems with the battery and sent me a new one after I gave them the number off the bottom of the battery. The original battery was marked "Made in China," and the replacement battery is marked "Cells made in Japan, assembled in China."



This did not change the charging characteristics. No matter what the state of charge of the battery, it takes about 8 hours for the light to turn from red to green.

I bought a Portapow USB and DC Power Monitor to check the charging rate (I didn't buy it just for this, I wanted to to check all of my USB chargers and cables anyway).

Here's what I found:

With the battery fully charged and the green light on, it read 4.19V and also showed 100% on a ZTS MBT-1 battery tester.




I then plugged it back into the charger which was connected to the USB tester and found that the output voltage from the USB charger was 5.18V, but the charging current was very low, only 20mA. After 20 minutes, it had only charged the battery 7mAh. I was satisfied that the battery was fully charged, and beginning to believe that the light was not an accurate indicator of charging status.

I then ran the flashlight on high for 30 minutes. The battery voltage was 3.77V and the ZTS said 60% (I didn't let the battery rest before taking the voltage reading). I then put it back on the charger and the charging voltage was 5.15V, and the charging current was 360mA. This is where I make the assumption that the maximum charging rate is about 360mA (and that the USB charger for this flashlight from Streamlight, which I don't have, is only a 500mA charger). The photo below was taken near the end of the charging cycle.



After about 3.5 hours (I forgot to write down the exact time), the charging current had tapered to about 28mA, and the battery had been charged about 866mAh. This makes sense because 40% (the amount the battery needed be charged) of 2200mAh (the capacity of the battery) is 880mAh. The charging light was still red. I've recharged a full battery enough to know that the light would stay red for about another 4.5 hours before it would turn green.



At this point I terminated the test because I was satisfied that the battery was fully charged. The voltage was 4.19V and the ZTS tester said 100%. Perhaps I could have gone a little longer, but I was happy with the results. From now on, I will use the ZTS tester to determine battery charge, and watch the charging current and mAh on the USB tester to determine when the battery is charged and ignore the light.

I don't know if I will contact Streamlight about this, other than sending me a new battery the customer support people wanted me to return the flashlight. I asked if they could check with their engineering staff who must know if this is normal, but they said no. My guess is that the customer support people are not very technical and if they can't quickly resolve an issue on the phone they will just turn it over to the repair people. This is not a slam on Streamlight, I'm sure if I sent the light in they would look into it.

Unless someone else who has this exact light can tell me if their light takes about 8 hours to turn from red to green with a fully charged battery, I'm just going to live with it.

I haven't noted how long it takes to charge. I may run a similar test and report back...

Thanks dano!

I should also mention that I'm using a 12W 2.4A Apple USB charger, which is overkill since the Streamlight charger is only 500mA and the maximum charging current I've observed is 360mA.

Streamlight mentions in the instructions that they recommend a 1000 mah charger. So, I used a 2400 mah, just in case. Using the same USB tester, I got an average of 500 mah during the charge. I noticed that the light was finnicky when the tester was used, i.e. false green light (full charge indicator).

Thanks dano, I've been doing some more testing too, but it'll probably be tomorrow before I can report back since I have to go out of town today.

When you say you're using the same USB tester, do you mean the Portapow like shown in my pictures?

Also, which battery do you have, the Chinese or Japanese one?

Dr. Strangelove said:

Thanks dano, I've been doing some more testing too, but it'll probably be tomorrow before I can report back since I have to go out of town today.

When you say you're using the same USB tester, do you mean the Portapow like shown in my pictures?

Also, which battery do you have, the Chinese or Japanese one?

Click to expand...

Yup, Portapow. And my cell is made and assembled in China. I didn't know about Japanese ones, I'll check my stash to see if I have one.

Well, I've figured it out, kinda.

The Portapow has never caused a problem while charging, because it has an internal battery it has minimal circuit loading.

I've found when I use an Apple charger (1A or 2.4A), the charging indicator light takes a long time to turn green even though the battery is charged (4.19V resting, 100% on the ZTS tester) and the charging current has tapered off to about 20mA. But when I plug it into a USB wall charger (the type built into a wall outlet, or in this case, a desk outlet), the light immediately turns green. Plug into the Apple USB charger: red, plug into the USB wall charger: green. Are you using an Apple charger? All of my wall warts are Apple.

Don't know why this is, maybe something to do with the data lines? I'm going to order the Streamlight charger and not worry about it, it only costs $6. Now that this is resolved, I'm 100% percent satisfied with this flashlight, in fact I might buy a second one.

Here's the setup:



The USB ports on the left work OK, the Apple charger to the right is nicht richtig! BTW, the maximum output from the USB ports is 1A.

Your thoughts dano?

Interesting, i noted the same thing with an Apple wallwart. I used an Ikea charger, and double checked that Apple charger behavior. I bet there's some funky algorithm in the Apple charger so the charger doesnt cook ipod batteries.

dano said:

Interesting, i noted the same thing with an Apple wallwart. I used an Ikea charger, and double checked that Apple charger behavior. I bet there's some funky algorithm in the Apple charger so the charger doesnt cook ipod batteries.

Click to expand...

Thanks dano, it's good to know it's not just me. I have a Streamlight USB charger arriving from Brightguy today, it's only $6.00. Carla with Streamlight Customer Service was very helpful to me (she sent me the new battery). I'll send her an email next week letting her know what we found. They probably don't know about this, I'm sure others will experience the same problem thinking that all USB chargers are the same.

Otherwise, I love this flashlight!

For the record, Streamlight customer service is great!